Pre-Turbo Meth Build

Hey Guys,

I have finally sorted my clutch out and decided it would be nice to get another project going on this car. I want to get more power out of it (around 430whp on E85 atm) but realize I am up against the cost wall on this platform. I can't afford to buy RB or Vargas turbos at the moment since that would mean not only the turbos but also the Cobb, fuel pump, and probably down pipes. Additionally that is a commitment to this car that is kind of outside of the scope of a DD. This is not my project car.

I could just turn up the boost on the stockers and run post turbo meth for octane/cooling/fuel but I am not comfortable driving the turbos that hard since they already have a little whine when cold (been running 17.5 psi for the past 30k miles). I did some research and figure that pre-turbo meth may be a viable option to lowering PWM. The concept is that the meth/water mix will suck up the heat while the turbos are compressing and thus your outlet temps will be near or slightly above ambient. Obviously air out of the turbos at 100F is a lot more dense than the 300-350F I am pushing now. Denser air takes less space, less space means each turn of the compressor contains more air, more air per turn means less shaft speed on the turbos, end result I can theoretically turn up the boost to fit within the same shaft speed window.

There are some limitations/issues here:

1. I can't measure shaft speed directly. If I had a shaft speed sensor and a thermocouple at the turbo outlet, that would be great, but that's beyond this experiment and my wallet. For this setup, PWM will be used as an approximation of how fast/hard the turbos are running.
2.Terry tested a pre-turbo/post turbo meth setup and saw no change in PWM. This is not good news for this test, but I want to try it nonetheless
3. Impingement: This is essentially erosion of the compressor wheels. This happens when the meth/water mix is still in droplet form and not totally vaporized when it hits the compressor.

Number 3 is obviously the biggest issue and I have spent some time researching and thinking about it. For this reason I have decided to go with a mechanical methanol injection setup. Mechanical methanol injection setups claim to have finer droplets than the electrical setups currently offered for the 335i. They function by using boost pressure to push the fluid into a 2-port atomizing nozzle. The other port is boost air. The boost air shoots across the liquid stream causing it to break up into a finer mix and evaporate quicker than if the methanol was injected into the air alone. That means methanol will be injected at ~17psi with ~20psi air pressure to break the droplets up.

I am not concerned about impingement for the following reasons:

1. Mechanical meth nozzles should create smaller drops
2. We already spit PCV oil into the turbos in some quantity and those drops are much more likely to be large. No erosion yet.
3. Flow is largely based on boost pressure rather than RPM. Unlike the electrical setups, flow varies with boost which should help reduce the amount of time that full meth flow is happening.

Criteria for success:

1. Nothing breaks and no meth fires
2. 500whp as measured by VirtualDyno (I am at 430whp now) in the same or slightly larger PWM window

Before we go any further, here is fair warning. This may not work out at all. This may damage turbos. I do not recommend any one to try and of this.

If I had to guess, power will stay pretty much the same as with post-fmic setups since you're basically introducing meth earlier in the system and given the size of our turbos the change won't have much effect on the power side of things. Of course, I'd love to be proven wrong. However, a reduction in PWM will most likely be there, not sure how much it might be reduced, and it might be worth it for just this reason in the end given your car is a DD and you'd like to push high boost while taxing the turbos less.

It sounds like an interesting project. In my experience the gains with pre-turbo injection are relatively minor but I'm not sure anyone has done it the way you are trying before. I guess you never know!

It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please see http://www.burgertuning.com/emissions_info.html for more information on legal requirements related to use of BMS parts.

1. Aquamist 100-1200 ml/min flow sensor (some say it really does 1500ml/min)
2. Custom voltage divider required to allow Aquamist sensor to read full scale. (default only would read to 300ml/min or something)
3. New air filters with flat tops. Since the BMS DCI I have not is conical in the center it will not work.
4. Meth/boost line
5. Trunk tank
6. Meth filter, meth solenoid to be JB4 controlled, and 2 atomization nozzles.

Voltage Divider

I am pretty proud of this one. Black is ground, red is +12V (really ~13.5), and green is the 5V output to the sensor which will force it to read full flow. I made this using proto board and encased the whole thing in hot melt glue.

Atomization Nozzle

These nozzles are set to 45 degree spray pattern which I chose to work well with the filters I am using. I didn't want to spray the filter element, but at the same time didn't want to go to too tight of a pattern because I am guessing that would mean worse atomization.

The air flow should keep the spray from any excessive wall wetting at the filter.

Filters

Unfortunately the tops of these are too thick and not nearly as rigid as I had hoped. I will be using some aluminum plate to keep the spray on target. This is how far I have gotten at this point in time.

Next Steps

1. Strap the tank down to the amp cover in the trunk.
2. Lay meth/boost line
3. Tap the intake manifold for sense and boost
4. Wire it all up to the JB4

I really hope this works out and leads to the advancement of the platform. Any comments and advise welcome. To start, does anyone know a good location to pull +12V off of for the solenoid and flow sensor? Is it cool to just piggyback it off of the NLS/JB4/etc port in the ECU box?

If I had to guess, power will stay pretty much the same as with post-fmic setups since you're basically introducing meth earlier in the system and given the size of our turbos the change won't have much effect on the power side of things. Of course, I'd love to be proven wrong. However, a reduction in PWM will most likely be there, not sure how much it might be reduced, and it might be worth it for just this reason in the end given your car is a DD and you'd like to push high boost while taxing the turbos less.

I should of clarified. I am not expecting to gain meaningful power from the pre-turbo meth portion. I plan to drive PWM down using the meth and then crank the boost back up to get the power so long as I stay within the same or little larger PWM limits.

It sounds like an interesting project. In my experience the gains with pre-turbo injection are relatively minor but I'm not sure anyone has done it the way you are trying before. I guess you never know!

Terry, any clue where I can get a +12V and a solid ground for the flow sensor and solenoid? I assume ground is decent anywhere on the chassis, but the 12V is probably easiest off of the same connector as the JB4/NLS? Is there any current issues there now that I would be stacking NLS, JB4, and solenoids+flow sensor?

Let me suggest something. Wouldn't it be easier to use the DV nipples as an injection point?

Not sure I follow? The meth/air is going to spray out of those clunky nozzles at 45 degrees. If I don't put them inline with some distance of pipe, they will spray right on to the wall of the intake tubing. While this isn't a big deal for conventional setups, it could be for this one. I don't want to take the risk of wetting the wall and eroding the side of the compressor wheel.

Terry, any clue where I can get a +12V and a solid ground for the flow sensor and solenoid? I assume ground is decent anywhere on the chassis, but the 12V is probably easiest off of the same connector as the JB4/NLS? Is there any current issues there now that I would be stacking NLS, JB4, and solenoids+flow sensor?

If the current draw is less than a couple amps just use the green switched power wires the JB4 uses. Use any chassis ground.

It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please see http://www.burgertuning.com/emissions_info.html for more information on legal requirements related to use of BMS parts.

Its still a lot of money, I would need many supporting mods, and the install seems like a PITA. Plus I wouldn't be learning anything or advancing the platform. If this works out, I can still get RBs and inject meth preturbo for even more power.

Thats what im saying. eventually, you will see the stockers are tapped. you are limited from the get-go. sure you can reduce its effects, but at some point hardware will be the limiting factor. Im not saying dont do what your doing, but i would financially and mentally prepare for hardware upgrades to achieve your goals

Thats what im saying. eventually, you will see the stockers are tapped. you are limited from the get-go. sure you can reduce its effects, but at some point hardware will be the limiting factor. I m not saying dont do what your doing, but i would financially and mentally prepare for hardware upgrades to achieve your goals

Oh yes, always. Try this first, doesn't get me where I want to be, I will re-evaluate then. I see a pretty big bill coming up though for chassis mods. This chassis just isn't set up for 400+ whp.

It sounds like you have done some research, and are comfortable with the hardware installation. However, I have a few questions that should encourage you to dig deeper:

From a mass flow perspective, is water or meth injection pre-turbo more effective? Again, you are focused on increasing the mass flow potential of the compressor assembly, so this question is aimed ONLY at this.

Would you not be better served by placing the injection nozzle directly in front of the compressor inlet? Even fuel injectors, which have smaller droplet size than what you are looking to do, achieve a fair amount of "wall wetting" where fuel puddles along the inlet port. Lets say you achieve a droplet size of 50 microns, which is pretty darn fine and close to what a quality fuel injector can do, what is keeping these droplets suspended in the airflow around bends?

Measuring WG DC as a means of monitoring the total effect is a messy approach. It sums many factors together including intercooler efficiency, and combustion, which both can be affected by the presence of water or meth. I would suggest to use 4 sensors on at least 1 turbo if you can't afford to put a turbine speed sensor in place. (Debatable if it can be used anyway...I'm having issues with the kit from Garret) The sensors would monitor intake pressure and temp, as well as compressor outlet temp and pressure. From these 2 parameters, you will be able to directly monitor the effect of pre-compressor injection.

My last question is related to the control of fluid flow into the compressor inlet. What method of injection will you use? Progressive flow versus injector duty cycle, progressive flow versus engine speed, progressive flow versus calculated air mass flow? Something to think about: Your turbo needs the effect of pre-compressor injection at lower efficiency points to help boost mass flow. By using a 3D table that targets mass flow versus turbine speed, you would be able to meter the optimal fluid injection volume for each compressor operating point.

No head spinning yet, but I am glad you're bringing up good questions some of which are unknowns that will just have to be figured out.

Originally Posted by PEI330Ci

From a mass flow perspective, is water or meth injection pre-turbo more effective? Again, you are focused on increasing the mass flow potential of the compressor assembly, so this question is aimed ONLY at this.

I am not 100% sure, but I believe water to be more effective IF you can get full atomization. Meth should be slightly less effective, but more likely to vaporize quickly. That being said I am running 50-50 blend for starts since I also need the fueling meth supplies and I am not comfortable injecting 100% meth into the turbos yet (or potentially ever). In either case, best blend is something that can be determined later on in the project need be.

Originally Posted by PEI330Ci

Would you not be better served by placing the injection nozzle directly in front of the compressor inlet? Even fuel injectors, which have smaller droplet size than what you are looking to do, achieve a fair amount of "wall wetting" where fuel puddles along the inlet port. Lets say you achieve a droplet size of 50 microns, which is pretty darn fine and close to what a quality fuel injector can do, what is keeping these droplets suspended in the airflow around bends?

Maybe. I have thought about wall wetting and am hoping that an insignificant amount of the mix ends up adhering to the walls. If the mix is fully atomized you would expect no wetting of the walls. If the tubes were cold, which they rarely should be, you would see some condensation. That being said, in a less than ideal world I may have some wall wetting. I will research more. I should be able to make the majority of drops in the 10-25 micron range with these nozzles.

Originally Posted by PEI330Ci

Measuring WG DC as a means of monitoring the total effect is a messy approach. It sums many factors together including intercooler efficiency, and combustion, which both can be affected by the presence of water or meth. I would suggest to use 4 sensors on at least 1 turbo if you can't afford to put a turbine speed sensor in place. (Debatable if it can be used anyway...I'm having issues with the kit from Garret) The sensors would monitor intake pressure and temp, as well as compressor outlet temp and pressure. From these 2 parameters, you will be able to directly monitor the effect of pre-compressor injection.

I agree its ghetto. I plan to monitor PWM back to back as a starting point. The next best option is compressor temperature/pressure out (and maybe in) and the gold standard would be shaft speed. Can you recommend a 4 input logging box with a relatively easy to use interface? I wouldn't mind getting it set up if it was economic. Piping to the front of the IC seems easy enough to access as is the intake tubing.

Originally Posted by PEI330Ci

My last question is related to the control of fluid flow into the compressor inlet. What method of injection will you use? Progressive flow versus injector duty cycle, progressive flow versus engine speed, progressive flow versus calculated air mass flow? Something to think about: Your turbo needs the effect of pre-compressor injection at lower efficiency points to help boost mass flow. By using a 3D table that targets mass flow versus turbine speed, you would be able to meter the optimal fluid injection volume for each compressor operating point.

Nothing that complicated. The flow will be progressive off boost pressure. The flow will start when boost hits my minimum threshold which will be modulated using a boost switch and solenoid that I will probably set around 11-12psi. The flow will be monitored by the Aquamist sensor and that data will be fed into the JB4 just like any other meth kit. The difference being that the flow will be variable, instead of on/off. The JB4 will then add boost only when it sees flow. The amount of boost to add is TBD and will be based off PWM for starts. I will log no meth PWM, then meth PWM with 0 add. If I see a difference in PWM between the two, I will then start increasing the additive until PWM is the same between the two.

I created a backing plate for the top of the filters which should keep the nozzles more rigidly mounted and pointing straight down the intake tubing. Unfortunately AEM doesn't have the highest level of consistency in their manufacturing process. One filter needed some gasket to provide the proper spacing:

Here you can see the discrepancy in the top thickness:

The nozzles are totally solid now and I feel much more confident that they won't wet the filter element:

Also got the tank mounted and into the car. I decided to strap it down to the amp cover:

Its the perfect size and came out pretty clean.

Next up I am laying meth/boost line. Unfortunately I knocked two tires out (sidewall puncture ugh), so that may set me back a bit. Sucks losing a set of PSS ($1400+).

I am not 100% sure, but I believe water to be more effective IF you can get full atomization. Meth should be slightly less effective, but more likely to vaporize quickly. That being said I am running 50-50 blend for starts since I also need the fueling meth supplies and I am not comfortable injecting 100% meth into the turbos yet (or potentially ever). In either case, best blend is something that can be determined later on in the project need be.

I don't have data to support the theory, but from what I understand, water is a better medium to be injected into the compressor stage. And as far as vaporizing goes, it appears that keeping the medium in liquid form, albeit in super low mass droplets, and allowing the phase change to occur inside the compressor is the most efficient.

Again, I think the focus needs to be on optimizing compressor efficiency with respect to mass flow. I think that focusing on changing pre-compressor air temps with 100% meth may be less effective than changing the adiabatic efficiency of the compressor.

Also, I'm not someone just sitting on the bench with this stuff....I've invested thousands in sensors and instrumentation to accurately measure this exact scenario. I just need to get my car back on the road....

Originally Posted by rudypoochris

Maybe. I have thought about wall wetting and am hoping that an insignificant amount of the mix ends up adhering to the walls. If the mix is fully atomized you would expect no wetting of the walls. If the tubes were cold, which they rarely should be, you would see some condensation. That being said, in a less than ideal world I may have some wall wetting. I will research more. I should be able to make the majority of drops in the 10-25 micron range with these nozzles.

Without getting too technical, it is possible for droplets to fall out of suspension, and also vaporized liquid to change back to liquid in a charge pipe. The charge pressure varies widely within a charge pipe depending on flow angles. For example, the inside radius of a bend will have lower pressure than the outside radius.

You may also find that the spray lowers the surface temp of the charge pipe to the point of causing condensation over a period of time. Who knows what the time is...but it would be a factor.

Originally Posted by rudypoochris

I agree its ghetto. I plan to monitor PWM back to back as a starting point. The next best option is compressor temperature/pressure out (and maybe in) and the gold standard would be shaft speed. Can you recommend a 4 input logging box with a relatively easy to use interface? I wouldn't mind getting it set up if it was economic. Piping to the front of the IC seems easy enough to access as is the intake tubing.

He he...it's more than most people ever consider, just trying to discuss the next step. I'm not an expert.

Logger: Innovate Motorsports LMA-3

It's pretty versatile...and gives you other options for performance measurement for your "next" project. The only down sides are that you need to have a PC connected to it to log, and that the logging rate is approximately 12 times a second. The setup I'll be using will have logging rates up to 1000 times a second. (But I'll also be logging over 100 engine parameters)

Originally Posted by rudypoochris

Nothing that complicated. The flow will be progressive off boost pressure. The flow will start when boost hits my minimum threshold which will be modulated using a boost switch and solenoid that I will probably set around 11-12psi. The flow will be monitored by the Aquamist sensor and that data will be fed into the JB4 just like any other meth kit. The difference being that the flow will be variable, instead of on/off. The JB4 will then add boost only when it sees flow. The amount of boost to add is TBD and will be based off PWM for starts. I will log no meth PWM, then meth PWM with 0 add. If I see a difference in PWM between the two, I will then start increasing the additive until PWM is the same between the two.

There isn't much out there on the market that can do a 3D table as described for PWM control. In fact, I'm currently waiting for 2 products to release some features so that I can evaluate whether it will work for me.

The Aquamist sensor is OK, and I'll be using a couple myself, but don't use it as a reference of absolute fluid flow. The only products I would use for that are from GILS sensor, and Siemens has a range of Coriolis flow measurement devices. Break out your wallet though....

Bear in mind, I am a 24 year old working out of my parents basement, just to give you an idea of my budget here. Haha.

I agree with your general assessment on most all of these things. I don't necessarily have all the answers even though I know someone probably does. Up until this point I have been concerned purely with the qualification of the concept. Most of your questions will be answered with greater ease and more definitively through testing. I am all for the theory, but there are so many unknowns at this point that I feel testing will yield more meaningful data. After this first round of testing, of course I can nail the mix down and all of that.

I have reached out to Terry to see if I can hijack a pair of 0-5v inputs on the jb4. That's only 10hz, but there is a certain simplicity going that route that I like.

I am all for the theory, but there are so many unknowns at this point that I feel testing will yield more meaningful data.

I totally agree with you.

I haven't been able to find proper data supporting answers to a number of my own questions....so I'm doing it myself.

One thing I've found is that usually pre-turbo and post-intercooler injection systems are tied together if a car is running both. From the little that I understand of the theory, it appears that each scenario could benefit from a slightly different injection method and control strategy. So I think there is something to be gained there as well....

I look forward to the results of your testing, whatever the outcome may be.

Nice project. Are you injecting post-IC also? When you mention mechanical, you are activating pump with pressure switch and controlling solenoid with JB4? Why the 2 inlet nozzles… does this mean 3 splitters?

The limited WGDC eval I’ve tried its hard to reach a conclusion unless the difference is substantial… like >5%. A thought would be to get a test map from Terry (if possible) running X% DC at WOT and then check the psi difference on/off pre-turbo meth. I’m sure there is a logging channel for checking PID from base though, which I haven’t used… not sure if JB is a defined base map, or still some piggybacking off the DME.

Most pre-turbo injection with other platforms (LSx, supra) is at the compressor vaporizing across the blades, but this would be quite difficult in labor rigging this up for the n54. For us I think we have to be concerned with all the liquid vaporizing before the blades… if this is a concern, more meth% seems to be better.

I’ve thought about just adding 1 0.5mm nozzle in the airbox. Worst case is unequal distribution between banks making 1 turbo more efficient, but this is still beneficial.